JPH0892190A - Cyanobiphenyl derivative and liquid crystal composition containing the derivative - Google Patents

Abstract

PURPOSE: To provide a new liquid crystal derivative having a large negative Δεand remarkable SmA phase developing capability and useful for the preparation of a liquid crystal composition for τ-Vmin mode method to expand also the SmC phase. CONSTITUTION: This derivative is expressed by formula I [R<1> and R<2> are each a 1-14C alkyl; the ring A is group of formula H, etc.; the ring B is group of formula III, etc., (the total number of CN groups of the rings A and B is 1 or 2 and the ring B is not the group of formula III when the ring A is the group of formula II)], e.g. 3-cyano-4-octyloxy-4'-decyloxybiphenyl. The derivative of formula I wherein A is group of formula II or B is group of formula III can be derived from a compound produced by coupling a compound of formula IV with a compound of formula V in the presence of a Pd catalyst.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel liquid crystal compound and a liquid crystal composition containing at least one of these liquid crystal compounds. More specifically, the present invention relates to a ferroelectric liquid crystal composition, a liquid crystal compound having a novel cyanobiphenyl skeleton which is useful as a composition component thereof and is excellent in chemical stability, and these liquid crystal compounds. And a liquid crystal composition containing at least one of the above.

[0002]

BACKGROUND ART Liquid crystal display devices are widely used as display devices for watches, calculators, personal word processors, pocket televisions and the like. This is because it has excellent characteristics such as a light-receiving type that does not cause tired eyes, consumes less power, and is thin, but the nematic liquid crystal composition has a slow response speed and no memory property. Therefore, there were restrictions in terms of application.

In order to expand the application field, a super twisted nematic (STN) type display element, which is an improvement of the conventionally used twisted nematic (TN) type display system, has been found. However, these are C
Since the response speed is slower than that of a display system such as RT and the viewing angle is not sufficient, researches on liquid crystal display elements to replace them are actively conducted, and one of them is a ferroelectric liquid crystal [R. B.
Meyer et al .; Physique, 36L-69 (19
75)] is used as a display method [N. A. Clark et al .;
AppliedPhy. Lett. , 36 899 (1
980)] is proposed. This system has excellent characteristics such as a high-speed response of 100 to 1000 times higher than that of the conventional system and has a memory property, and thus is expected to be used for a wider range of liquid crystal display devices. Ferroelectric liquid crystal refers to a series of smectic liquid crystals in which the long axis of the liquid crystal molecule has an angle with the layer normal direction, but in practice a chiral SmC phase is used.

As a ferroelectric liquid crystal composition for producing a display device, a liquid crystal composition system in which various compounds having a chiral SmC phase are mixed, or a liquid crystal compound having an SmC phase, or a liquid crystal composition and an optically active compound are used. There are two methods of mixing with a compound to form a liquid crystal composition having a chiral SmC phase. In the research and development of the ferroelectric liquid crystal display element, the liquid crystal composition obtained by the method was initially used, but the research progressed, and the ferroelectric liquid crystal was added by adding the optically active compound to the compound having the SmC phase. Since it was found that the above-mentioned composition was obtained, the direction of using the composition obtained by the above-mentioned method tends to gradually increase.

For a practical ferroelectric liquid crystal composition, a wide temperature range of the chiral SmC phase, an appropriate phase sequence, and a chiral S
Various properties such as long helical pitch in mC phase, proper tilt angle, proper spontaneous polarization, and fast response are required.
These properties are dependent on the host liquid crystal that occupies most of the liquid crystal composition except for the spontaneous polarization and the helical pitch, and in order to optimize these properties, it was tried to mix various compounds. Has been. As the mixed component, one having an SmC phase is better, but it is not always necessary to have the SmC phase as long as the above-mentioned object can be achieved.

For example, in order to manufacture a display having a high contrast and a wide viewing angle, it is essential to obtain a good alignment state of liquid crystals. The orientation of the ferroelectric liquid crystal composition is performed by gradually cooling the isotropic liquid to the chiral SmC phase, and the phase series is an important factor in this case. Generally, in order to obtain a good orientation, Iso. → chiral Ne → S _A → chiral Sc or Iso. → S
_A → Chiral Sc phase sequence is required. This is Sm
Since the C phase has a layered structure and the long axis of the molecule is inclined with respect to the layer normal direction, the molecules are well aligned in the chiral Ne phase having no layered structure or when cooled from an isotropic liquid. This is because even if it is done, the direction of the layer is difficult to be determined, but the presence of the SmA phase having the same layer structure and having the molecular long axis and the layer normal direction coincides solves the above problem. Thus, the SmA phase plays an important role in terms of orientation. Sm
A liquid crystal composition having an appropriate phase series can be obtained by adding a compound having a strong SmA phase to a composition having no A phase or having a narrow SmA phase temperature range.

Even if the compound itself to be added does not have the SmC phase, it is possible to stabilize and expand the SmC phase of the host liquid crystal compound or the host liquid crystal composition by adding the compound. Such a compound is also important as a compounding component of the liquid crystal composition.

Further, as a driving method of a ferroelectric liquid crystal display element, a τ-V _min mode method has attracted attention. This mode method has advantages such as high-speed switching, high contrast, and a wide drive range in line address time, and is an effective mode for multiplex drive [J. P. Hughes et al .; Liq. Crys
t. , 13 (4) 597 (1993)]. The host liquid crystal used in this mode has a negative dielectric anisotropy (Δε <
0) [H. Orihara et al .; JpnJ.
Appl. Phys. , 25 L839 (1986),
P. W. H. Surguy et al .; Ferroselectr
ics 122 63 (1991)], the molecular structure requires a strong dipole moment in the minor axis direction of the molecule. However, by adding a compound of Δε <0 to a liquid crystal composition of Δε> 0, it is possible to prepare a composition of Δε <0 as a whole, and in this case also, the added compound does not necessarily have a SmC phase. No need.

For the purpose of providing a liquid crystal compound effective in preparing a liquid crystal composition for the τ-V _min mode method, the present inventors have prepared a cyano group having a strong electron-withdrawing property on the side of the long axis of the molecule. By introducing and combining with a fluorine atom and a trifluoromethyl group, we designed a compound that is expected to increase the dielectric constant in the direction perpendicular to the molecular long axis (Δε becomes large negative), and synthesize these compounds. However, as a result of earnestly researching by making individual compounds and compositions containing them, Δε is negatively large, the SmA phase expression ability described above is large, and the SmC phase is extremely useful material substance. Found out. The present invention is based on such findings.

[0010]

DISCLOSURE OF THE INVENTION The present invention has the general formula (I)

[Chemical 5] (In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 14 carbon atoms,

[0011]

[Chemical 6] The present invention also provides a novel cyanobiphenyl derivative represented by: and also provides a liquid crystal composition containing at least one liquid crystal compound thereof.

The synthetic route of the liquid crystalline compound according to the present invention will be described below, and the present invention will be described in detail with reference to Examples and the like. Hereinafter, synthetic routes are shown and described, but they are merely examples, and the present invention is not limited by the examples as well as the examples.

[Synthesis Route Diagram] Each symbol in the formula has the above-mentioned definition.

[0014]

[Chemical 7]

[0015]

Embedded image

[0016]

[Chemical 9]

[0017]

[Chemical 10]

[0018]

[Chemical 11]

[0019]

[Chemical 12]

[0020]

[Chemical 13]

[0021]

Embedded image

The synthetic route represented by the formula will be described below.

[Chemical 15]

[Chemical 16] Coupling reaction with a palladium catalyst, or

[0023]

[Chemical 17]

Next, the compound

[Chemical 18] The synthetic route of is explained.

In the following description, the notation of each compound is
The number attached to the formula of each compound shown in the above-mentioned synthetic route diagram is used as it is to represent the compound.
Compounds 1- (1), 1- (5), 1- (8), 1- (1
3), 1- (18), 1- (25), 1- (29), 1
-(33) is commercially available.

Compound 1- (1) is etherified by a conventional method using alkyl bromide (R ¹ Br) to obtain compound 1- (2).
Compound 1- (3) by bromination with r ₂ )
Is obtained. Further, the compound 1- (3) is lithiated with butyllithium (C ₄ H ₉ Li), and then trimethyl borate [B (OCH ₃ ) ₃ ] is caused to act on the compound 1 to hydrolyze it with dilute sulfuric acid to give the compound 1- ( ₃ ). (4) is obtained.

Compound 1- (5) was etherified with alkyl bromide (R ¹ Br) to give compound 1-
(6) is obtained, and trifluoromethanesulfonic anhydride [(CF ₃ SO ₂ ) ₂ O] is allowed to act on it to obtain compound 1- (7). Compound 1- (8) was alkylated with alkyl bromide (R ¹ Br) to give compound 1- (9), which was then lithiated with lithium diisopropylamide [(C ₃ H ₇ ) ₂ NLi]. ,
Compound 1- (10) is obtained by reacting dimethylformamide [HCON (CH ₃ ) ₂ ]. Compound 1- (10) was converted into hydroxylamine hydrochloride (HONH
Compound 1- (11) is obtained by converting the oxime with [ ₂ · HCl] and then performing a dehydration reaction.

Compound 1- (12) can be obtained from compound 1- (11) by carrying out the same procedure as described above for obtaining compound 1- (4) from compound 1- (3). Compound 1-
Compounds 1- (11) and 1- (12) are obtained from (8), and the same operation is performed to obtain compounds 1- (16) and 1- (17) from compound 1- (13). Compound 1
- (18), 1- (13), from 1- (8), by etherification with alkyl bromide ^(R 2 Br), respectively compound 1- (19), 1- (21), 1- (2
3) was obtained, and these were converted to butyllithium (C ₄ H ₉ L
After lithiation with i), trimethyl borate [B
(OCH ₃ ) ₃ ] is allowed to act and hydrolysis is carried out to give compounds 1- (20), 1- (22) and 1-, respectively.
(24) is obtained.

Compound 1- (25) is etherified with alkyl bromide (R ² Br) to give Compound 1-
(26) was obtained, which was converted to butyllithium (C ₄
After lithiation with H ₉ Li) and reacting iodine (I ₂ ) with the compound 1- (28),
Compound 1- (27) is obtained by allowing trimethyl borate [B (OCH ₃ ) ₃ ] to act and hydrolyzing it.
After diazotizing the compound 1- (29) with sodium nitrite,
Compound 1- (30) is obtained by thermal decomposition. From compound 1- (18) to compound 1- (19), 1-
Compound 1- (30) was obtained by the same operation as that for obtaining (20).
To obtain compounds 1- (31) and 1- (32). From compound 1- (29) to compound 1- (31), 1- (3
Compound 1- (35) and 1- (36) are obtained from compound 1- (33) by the same operation as for obtaining 2).

[0030]

[Chemical 19] Bromination of compound 2- (1) with N-bromosuccinimide gives compound 2- (2), which is diazotized with sodium nitrite and then treated with potassium iodide to give compound 2- (2). 3) is obtained.

Compound 2- (3) and compound

Embedded image Compound 2- (4) was obtained by the coupling reaction with and under the palladium catalyst, and this compound was subjected to lithiation with butyllithium (C ₄ H ₉ Li) and then treated with trimethyl borate [B (OCH ₃ ) ₃ ]. Then, the compound 2- (5) is obtained by hydrolysis with dilute sulfuric acid.

Compound 2- (5) is oxidized with aqueous hydrogen peroxide to obtain compound 2- (6), which is etherified with alkyl bromide (R ¹ Br) to give compound 2- (6). (7) is obtained.

Compound 2- (3) and compound

[Chemical 21] Compound 2- (8) is obtained by the coupling reaction with and under a palladium catalyst. Compound 2- (7) was obtained from compound 2- (4) by the same procedure.
Compound 2- (11) is obtained from-(8).

Hereinafter, the present invention will be described in more detail with reference to Examples and the like. The abbreviations used in this specification have the following meanings. GLC: Gas chromatography HPLC: High performance liquid chromatography m. p: melting point b. p: Boiling point C: Crystalline Sx: Smectic phase with unknown distinction Sc: Smectic C phase S _A : Smectic A phase Ne: Nematic phase I: Isotropic liquid

[0035]

【Example】

[Chemical formula 22]

[Chemical formula 23] In a 1 liter flask, 61 g of 2-cyanophenol,
127 g of anhydrous potassium carbonate, 135 g of 1-bromooctane,
Acetone (500 ml) was charged, and the mixture was stirred under reflux for 20 hours. The reaction solution was poured into water, the organic layer was extracted with toluene, the toluene layer was washed with water, dried over sodium sulfate, the solvent was distilled off, and the residue was distilled under reduced pressure to obtain 2-octyloxybenzonitrile. . Yield 117g GLC: 100%
b. p: 140-142 ° C / 0.7 torr

[0036]

[Chemical formula 24] A 500 ml flask was charged with 50 g of 2-octyloxybenzonitrile and 130 ml of chloroform, and 70 g of bromine was added dropwise with stirring at room temperature. After gradually raising the temperature and stirring at the reflux temperature for 5 hours, the reaction solution was poured into water. The chloroform layer was washed with a dilute sodium hydroxide aqueous solution, a sodium thiosulfate aqueous solution, and water in this order, dried over sodium sulfate, and then the solvent was distilled off. The residue was distilled under reduced pressure and recrystallized from methanol to give 3-cyano-4.
-Octyloxybromobenzene was obtained. Yield 55.3
g GLC: 100% b. p: 161-165 ° C / 0.
7 torr m. p: 33-35 ° C

[0037]

[Chemical 25] A 100 ml flask whose inside was replaced with argon was charged with 5 g of 3-cyano-4-octyloxybromobenzene and 80 ml of dry tetrahydrofuran (THF). To this, 11 ml of a 1.6 M butyllithium-hexane solution was added at -80 ° C, and the mixture was stirred at the same temperature for 5 minutes, and then 4 g of trimethyl borate was added dropwise. After returning to room temperature and stirring for 5 hours, the reaction solution was poured into diluted sulfuric acid, and the organic layer was extracted with ether. The ether layer was washed with water and dried over sodium sulfate, and then the solvent was distilled off to obtain 3-cyano-4-octyloxyphenylboronic acid. Yield 3.3g HPLC: 94
%

[0038]

[Chemical formula 26] In a 1 liter flask, 4-bromophenol 100
g, 141-bromodecane 141 g, anhydrous potassium carbonate 136
g, 500 ml of 2-butanone were charged, and the mixture was refluxed at 20
Stir for hours. The reaction solution was poured into water, and the organic layer was extracted with toluene. After washing the toluene layer with water and drying with Glauber's salt,
The solvent was distilled off, and the residue was distilled under reduced pressure to obtain 4-decyloxybromobenzene. Yield 146g GLC: 98%
b. p: 143-145 ° C / 0.25 torr

[0039]

[Chemical 27] Tetrakistriphenylphosphine palladium [Pd (PPh
₃ ) ₄ ] 0.4 g, 4-decyloxybromobenzene 3
g of benzene solution (30 ml), 2M sodium carbonate aqueous solution (11 ml), and 3-cyano-4-octyloxyphenylboronic acid (2.8 g) in ethanol solution (20 ml) were charged, and the mixture was stirred at reflux temperature for 6 hours. The reaction solution was poured into water, and the organic layer was extracted with toluene. The toluene layer was washed with water and dried with sodium sulfate, and then the solvent was distilled off. Silica gel column chromatography of the residue (eluent toluene / hexane =
It was purified by 1/1) and recrystallized from acetone to give 3-cyano-4-octyloxy-4'-decyloxybiphenyl. Yield 1.2g HPLC: 99.4%

Results of IR measurement and Ma of the obtained compound
By ss analysis, it was confirmed that the obtained compound was the title compound from the fact that a molecular ion peak was found at 463 and a reference peak was found at 211 and the relationship of the starting materials used. This compound was used as a hot stage FP-8 manufactured by METTLER CORPORATION.
2 was used to observe the phase change under a polarizing microscope. The results are shown in Table 4.

[0041]

[Chemical 28]

[Chemical 29] In Example 1- (d), 4-bromophenol 10
75 g of 2,3-difluorophenol instead of 0 g
Was replaced with 141 g of 1-bromodecane, and 120 g of 1-bromooctane was used. Otherwise, the same operation as in Example 1- (d) was carried out to obtain 2,3-difluorooctyloxybenzene. Yield 130g GLC: 98%
b. p: 98 ° C / 0.25 torr

[0042]

[Chemical 30] In a 2 liter flask whose inside was replaced with argon,
-Difluorooctyloxybenzene 100 g, dried T
700 ml of HF was charged, to this was added 335 ml of 1.6 M butyllithium-hexane solution at -50 to -60 ° C, and the mixture was stirred at the same temperature for 2 hours. Next, 86 g of trimethyl borate was added dropwise, the temperature was gradually returned to room temperature, and the mixture was stirred overnight. The reaction solution was poured into diluted sulfuric acid, and the organic layer was extracted with ether. The ether layer was washed with water and dried over sodium sulfate, the solvent was distilled off, and the residue was recrystallized from hexane to give 2,3-
Difluoro-4-octyloxyphenylboronic acid was obtained. Yield 93.8 g HPLC: 94%

[0043]

[Chemical 31] In Example 1- (e), 3 g obtained in Example 1- (b) was used in place of 3 g of 4-decyloxybromobenzene.
3 g of cyano-4-octyloxybromobenzene 3 g
-Cyano-4-octyloxyphenylboronic acid 2.8
In place of g, 2.9 g of 2,3-difluoro-4-octyloxyphenylboronic acid was used, and otherwise, Example 1-
By the same operation as in (e), 3-cyano-4-octyloxy-2 ', 3'-difluoro-4'-octyloxybiphenyl was obtained. Yield 1.7 g HPLC:
99.8%

Results of IR measurement and Ma of the obtained compound
By ss analysis, it was confirmed that the obtained compound was the title compound from the fact that a molecular ion peak was found at 471 and a reference peak was found at 247 and the relationship of the starting materials used. This compound was used as a hot stage FP-8 manufactured by METTLER CORPORATION.
2 was used to observe the phase change under a polarizing microscope. The results are shown in Table 4.

[0045]

[Chemical 32]

[Chemical 33] In Example 1- (d), 4-bromophenol 10
2-fluoro-4-bromophenol 1 instead of 0 g
3-Fluoro-4-decyloxybromobenzene was obtained by the same procedure as in Example 1- (d) except that 10 g was used. Yield 143 g GLC: 98% b.
p: 145-148 ° C / 0.25 torr

[0046]

Embedded image A 500 ml flask whose inside was replaced with argon was charged with 4.4 g of magnesium and a small amount of iodine.
Fluoro-4-decyloxybromobenzene 50 g T
300 ml of the HF solution was added dropwise at 40 to 50 ° C., and the mixture was stirred at the same temperature for 1 hour to prepare a Grignard reagent. In a separate flask, 47 g of trimethyl borate and dry THF
100 ml was charged, and the Grignard reagent prepared above was added dropwise thereto at 0 to 5 ° C. After stirring at the same temperature for 2 hours and returning to room temperature overnight, the reaction solution was poured into diluted sulfuric acid, and the organic layer was extracted with ether. The ether layer was washed with water, dried over Glauber's salt, the solvent was distilled off, and the residue was recrystallized from hexane to obtain 3-fluoro-4-decyloxyphenylboronic acid. Yield 28g HPLC: 94%

[0047]

Embedded image In Example 1- (e), 3 g obtained in Example 1- (b) was used in place of 3 g of 4-decyloxybromobenzene.
3 g of cyano-4-octyloxybromobenzene 3 g
-Cyano-4-octyloxyphenylboronic acid 2.8
3-Fluoro-4-decyloxyphenylboronic acid 3 g was used in place of g, and the same operation as in Example 1- (e) was performed except that 3-cyano-4-octyloxy-3′- was used. Fluoro-4'-decyloxybiphenyl was obtained. Yield 2.8g HPLC: 99.6%

Results of IR measurement and Ma of the obtained compound
In the ss analysis, it was confirmed that the obtained compound was the title compound from the fact that a molecular ion peak was found at 481 and a reference peak was found at 229 and the relationship of the starting materials used. Using a hot stage FP-82 manufactured by METTLER CORPORATION, this compound was observed for phase change under a polarizing microscope. The results are shown in Table 4.

[0049]

Embedded image

Embedded image A 300 ml flask was charged with 20 g of 2-amino-5-bromobenzotrifluoride, 40 ml of water and 24 ml of concentrated sulfuric acid, stirred for a while, and then 60 ml of acetic acid was added. To this, 20 ml of an aqueous solution of 6.7 g of sodium nitrite was added dropwise at 0 to 5 ° C., ice pieces, 0.5 g of urea and 120 ml of acetic acid were further added, and the mixture was left at 5 ° C. or lower to prepare a diazonium salt solution. .

In a separate flask, add sodium sulfate 31.2
g, concentrated sulfuric acid 24 ml, and water 20 ml were charged, and 130
Heat to ~ 135 ° C. The diazonium salt solution prepared above was gradually added dropwise to this to distill the produced phenolic body together with steam. The distillate was extracted with ether, the ether layer was washed with water, dried over sodium sulfate, the solvent was distilled off, and the residue was distilled under reduced pressure to obtain 2-trifluoromethyl-4-bromophenol. Yield 15.3g G
LC: 92% b. p: 105 ° C / 30 torr

[0051]

[Chemical 38] In a 100 ml flask, 2-trifluoromethyl-4-
Bromophenol 15 g, 1-bromooctane 15 g,
26 g of potassium carbonate and 150 ml of 2-butanone were charged, and the mixture was stirred at reflux temperature for 20 hours. The reaction solution was poured into water, and the organic layer was extracted with toluene. The toluene layer is washed with water and dried over sodium sulfate, the solvent is distilled off, and the residue is distilled under reduced pressure to 3
-Trifluoromethyl-4-octyloxybromobenzene was obtained. Yield 18 g GLC: 94% b. p: 1
25 ° C / 1.5 torr

[0052]

[Chemical Formula 39] A flask whose inside was replaced with argon was charged with 18 g of 3-trifluoromethyl-4-octyloxybromobenzene and 100 ml of dry THF, to which 38 ml of a 1.6 M butyllithium-hexane solution was added dropwise at -70 ° C, and at the same temperature. It was stirred for 1 hour. Trimethyl borate (5.8 g) was added dropwise to the reaction solution, and the mixture was stirred at the same temperature for 2 hours and then returned to room temperature and stirred overnight, and then the reaction solution was added to diluted sulfuric acid. The organic layer was extracted with ether, the ether layer was washed with water, dried over sodium sulfate, the solvent was distilled off, and the residue was recrystallized from hexane to give 3-trifluoromethyl-4-octyloxyphenylboronic acid. Obtained. Yield 13.5g HPLC:
98%

[0053]

[Chemical 40] In Example 1- (e), 3 g obtained in Example 1- (b) was used in place of 3 g of 4-decyloxybromobenzene.
3 g of cyano-4-octyloxybromobenzene 3 g
-Cyano-4-octyloxyphenylboronic acid 2.8
In place of g, 3.2 g of 3-trifluoromethyl-4-octyloxyphenylboronic acid was used, except that in Example 1
By operating in the same manner as in (e), 3-cyano-4-octyloxy-3'-trifluoromethyl-4'-octyloxybiphenyl was obtained. Yield 3.7g HPL
C: 99.6%

Results of IR measurement and Ma of the obtained compound
In the ss analysis, it was confirmed that the obtained compound was the title compound from the fact that a molecular ion peak was observed at 503 and a reference peak was observed at 279 and the relationship of the starting materials used. Using a hot stage FP-82 manufactured by METTLER CORPORATION, this compound was observed for phase change under a polarizing microscope. The results are shown in Table 4.

[0055]

Embedded image

[Chemical 42] In a 2 liter flask, 2-aminobenzonitrile 10
Charge 1 g and dry methylene chloride 600 ml, -10
At 0 ° C., 153 g of N-bromosuccinimide was gradually added. After stirring at 0 ° C. for 2 hours, the reaction solution was washed with water and dried with mirabilite. The solvent was distilled off, and the residue was recrystallized from toluene to give 2-amino-5-bromobenzonitrile. Yield 142 g GLC: 98% m. p: 93-9
5.5 ° C

[0056]

[Chemical 43] A 3 liter flask was charged with 625 ml of concentrated hydrochloric acid and 142 g of 2-amino-5-bromobenzonitrile and stirred for a while. Add this to sodium nitrite 57 at -5 ° C.
300 g of an aqueous solution of g was added dropwise, and the mixture was stirred at 0 ° C. for 1 hour. To this reaction solution, 568 ml of cyclohexane was added, and 600 ml of an aqueous solution of 247 g of potassium iodide was added to 0 to 5
After dropping at 0 ° C., the mixture was returned to room temperature and stirred overnight. After injecting ether into the reaction solution and removing insoluble matter by filtration,
The ether layer was washed with water, a sodium sulfite aqueous solution, a sodium hydroxide aqueous solution, and water in this order. The solvent was distilled off, and the residue was washed by immersion in hexane to remove 2-iodo-5-
Bromobenzonitrile was obtained. Yield 119g GLC:
91%

[0057]

[Chemical 44] In Example 1- (d), 141 g of 1-bromodecane
Instead of using 123 g of 1-bromooctane,
By performing the same operation as in Example 1- (d), 4-octyloxybromobenzene was obtained. Yield 125g GL
C: 98% b. p: 122-124 ° C / 0.25 t
orr

[0058]

[Chemical formula 45] In Example 3- (b), 43 g of 4-octyloxybromobenzene was used in place of 50 g of 3-fluoro-4-decyloxybromobenzene, and Example 3-
By operating in the same manner as in (b), 4-octyloxyphenylboronic acid was obtained. Yield 24g HPLC: 95
%

[0059]

[Chemical formula 46] Tetrakistriphenylphosphine palladium [Pd (PPh
₃ ) ₄ ] 3 g, 150 g of a benzene solution of 24 g of 2-iodo-5-bromobenzonitrile, 65 ml of a 2M sodium carbonate aqueous solution, and 100 ml of an ethanol solution of 20 g of 4-octyloxyphenylboronic acid were charged and stirred at a reflux temperature for 6 hours. The reaction solution was poured into water, the organic layer was extracted with toluene, the toluene layer was washed with water, dried with sodium sulfate, and the solvent was distilled off. Silica gel column chromatography of the residue (eluent toluene / hexane = 1/1)
, And then recrystallized from hexane to give 2-cyano-4-bromo-4'-octyloxybiphenyl. Yield 9.6 g GLC: 96% b. p:
185-190 ° C / 0.15 torr m.p. p: 46.
2-48.0 ° C

[0060]

[Chemical 47] In a flask whose inside was replaced with argon, dry THF 20 m
1 and 17 ml of 1.6 M butyllithium-hexane solution were charged, and at −90 ° C., 30 ml of a THF solution of 9.6 g of 2-cyano-4-bromo-4′-octyloxybiphenyl was added, and the mixture was stirred for 5 minutes. did. Next, 6 g of trimethyl borate was added dropwise, and the mixture was returned to room temperature and stirred overnight.
The reaction solution was poured into diluted sulfuric acid, the organic layer was extracted with toluene, the toluene layer was washed with water, and the solvent was evaporated. The obtained viscous liquid was dissolved in 40 ml of THF, and 60 ml of 10% hydrogen peroxide solution was added dropwise thereto while cooling with ice water, followed by stirring for 3 hours. The organic layer was extracted with toluene, the toluene layer was washed with water, dried with sodium sulfate, and the solvent was distilled off. Silica gel column chromatography of the residue (eluent toluene /
Purified with ethyl acetate = 5/1), and further with hexane-
Recrystallization from a mixed solvent of acetone gave 2-cyano-4-hydroxy-4'-octyloxybiphenyl. Yield 5 g GLC: 99% m.p. p: 133.5-134.
9 ° C

[0061]

[Chemical 48] In a 100 ml flask, 2-cyano-4-hydroxy-
3 g of 4'-octyloxybiphenyl, 2.2 g of anhydrous potassium carbonate, 2.5 g of 1-bromodecane, 50 m of acetone
1 was charged, and the mixture was stirred at reflux temperature for 20 hours. The reaction solution was poured into water, the organic layer was extracted with toluene, the toluene layer was washed with water, dried with sodium sulfate, and the solvent was distilled off. The residue was purified by silica gel column chromatography (eluent toluene / hexane = 1/1) and recrystallized from acetone to give 2-cyano-4-decyloxy-4′-octyloxybiphenyl. Yield 3.6g HPL
C: 99.8%

Results of IR measurement and Ma of the obtained compound
In the ss analysis, a molecular ion peak was found at 463,
In addition, it was confirmed that the obtained compound was the title compound from the fact that it was the standard peak and the relation of the raw materials used. This compound was used as a hot stage FP-8 manufactured by METTLER CORPORATION.
2 was used to observe the phase change under a polarizing microscope. The results are shown in Table 4.

[0063]

[Chemical 49]

[Chemical 50] In a 500 ml flask, 2,3-dicyanohydroquinone 30 g, 1-bromooctane 40 g, anhydrous potassium carbonate 4
Charge 4 g and 200 ml of 2-butanone, and add 5 at the reflux temperature.
Stir for 0 hours. The reaction solution was poured into water, and the organic layer was extracted with toluene. The toluene layer was washed with water and dried with sodium sulfate, and then the solvent was distilled off. The residue is purified by silica gel column chromatography (eluent toluene), 2,3-
Dicyano-4-octyloxyphenol was obtained. Yield 4.9 g GLC: 98% m.p. p: 139-144.
5 ° C

[0064]

[Chemical 51] In a 50 ml flask, dry pyridine 20 ml, 2,3-
Dicyano-4-octyloxyphenol (4.9 g) was added, and trifluoromethanesulfonic anhydride (6.1 g) was added dropwise at 0 ° C., and the mixture was stirred at the same temperature for 2 hours and then returned to room temperature and stirred overnight. The reaction solution was poured into water, the organic layer was extracted with toluene, and the toluene layer was washed successively with water, diluted hydrochloric acid and water. The solvent was distilled off, and the residue was purified by silica gel column chromatography (eluent toluene),
2,3-Dicyano-4-octyloxyphenyl trifluoromethanesulfonate was obtained. Yield 7g GL
C: 98%

[0065]

[Chemical 52] In Example 3- (b), 50 g of 3-fluoro-4-decyloxybromobenzene was replaced with Example 1-
4-decyloxybromobenzene 47 obtained in (d)
4-decyloxyphenylboronic acid was obtained by the same procedure as in Example 3- (b) except that g was used. Yield 29g HPLC: 95%

[0066]

Embedded image Tetrakistriphenylphosphine palladium [Pd (PPh
₃ ) ₄ ] 1 g, 2,3-dicyano-4-octyloxyphenyl trifluoromethanesulfonate 6 g of dimethoxyethane solution 20 ml, 2M sodium carbonate aqueous solution 15 ml, 4-decyloxyphenylboronic acid 5 g of dimethoxyethane solution 40 ml were charged. , At reflux temperature 8
Stir for hours. The reaction solution was poured into water, the organic layer was extracted with toluene, the toluene layer was washed with water, and dried with sodium sulfate,
The solvent was distilled off. The residue was purified by silica gel column chromatography (eluent toluene) and further recrystallized from acetone to obtain 2,3-dicyano-4-octyloxy-4'-decyloxybiphenyl. Yield 3.7
g HPLC: 99.1%

Results of IR measurement and Ma of the obtained compound
From the ss analysis, it was confirmed that the obtained compound was the title compound based on the fact that a molecular ion peak was observed at 488 and a reference peak was detected at 236 and the relationship of the starting materials used. This compound is a hot stage FP- manufactured by METTLER CORPORATION.
82 was used to observe the phase change under a polarizing microscope. The results are shown in Table 4.

[0068]

[Chemical 54] A nematic liquid crystal composition (T _NI 69.
6 ° C.) A-1 was prepared, and for this composition,
5 to 20 wt% of each compound obtained in 6 was added, and the dielectric anisotropy (Δε) in the nematic phase was measured.
The results are shown in Table 1. The measurement of Δε was performed by the following method.

A vertical alignment cell (manufactured by EHC, orientation agent: hexadecyltrimethylammonium bromide) and a horizontal alignment cell (manufactured by EHC, orientation agent: Hitachi Kasei Polyimide LX-1400) were used, and each empty cell capacitance was measured. C _{1 and} C ₂ are produced by General Radio 1
Measured with 620A type capacitance bridge (±
0.5V, 1Kz sine wave). Next, the measurement sample was enclosed in two types of cells, and the electrostatic capacities C _{3 and} C ₄ of the vertical alignment cell and the horizontal alignment cell were measured in the same manner as described above, and Δε was calculated from the following formula. Δε = [C ₃ / C ₁ ]-[C ₄ / C ₂ ]

[0070]

[Table 1]

It was found that the compounds obtained in Examples 1 to 6 had already negatively shifted the Δε of the liquid crystal composition A-1 when added in a small amount. This suggests that Δε of the compounds obtained in Examples 1 to 6 is negatively large, and in preparing a liquid crystal composition, component materials for imparting a desired Δε, particularly, It is shown to be suitable as a liquid crystal material for the τ-V _min mode method.

Example 8 Liquid Crystalline Compound

[Chemical 55] On the other hand, Table 2 shows the phase series and the phase transition temperature when the compound obtained in Example 1 was added.

[0073]

[Table 2]

[0074]

[Chemical 56] Although it has a phase sequence of I → Ne → SmC, the SmC phase is a monotropic phase. By adding 10 wt% of the compound of Example 1 to this, ideal I → Ne
It was confirmed that the phase sequence was → SmA → SmC, and that the SmC phase was changed to the enantiotropic phase in the temperature range of 12 °. From the above, the compound of Example 1 is S
It was confirmed that there was a great effect on the expression of the mA phase and the stabilization and expansion of the SmC phase.

Example 9 Liquid Crystalline Compound

[Chemical 57] On the other hand, Table 3 shows the phase series and phase transition temperatures when the compounds obtained in Examples 3 and 6 were added, respectively.

[0076]

[Table 3]

Liquid crystalline compound

[Chemical 58] On the other hand, it was confirmed that the temperature range of the SmC phase and the SmA phase was expanded by adding 10 wt% of the compound obtained in Example 3. In addition, liquid crystal compounds

[0078]

Embedded image On the other hand, it was confirmed that the temperature range of the SmC phase was extended even when 5 wt% of the compound obtained in Example 6 was added.

[0079]

[Table 4]

[0080]

INDUSTRIAL APPLICABILITY The cyanobiphenyl derivative according to the present invention is effective in stabilizing and expanding the SmC phase and in expressing and expanding the SmA phase in the preparation of the liquid crystal composition. Further, since it has a large negative dielectric anisotropy, it can be used as a liquid crystal material for the τ-V _min mode method.
It is a useful material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsunenobu Fujii 1-7-1 Inari, Soka City, Saitama Kanto Chemical Co., Ltd. Central Research Laboratory

Claims (2)

[Claims] 1. A compound of the general formula (I) (In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 14 carbon atoms; A cyanobiphenyl derivative represented by. 2. A compound represented by the general formula (I): (In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 14 carbon atoms; A liquid crystal composition comprising at least one cyanobiphenyl derivative represented by: